Heat IllnessHeat3NCT01434979
Exertional Heat Illness: Biomarkers for Prediction and Return to Duty
An observational study of Heat Illness, run by Henry M. Jackson Foundation for the Advancement of Military Medicine at 2 sites in 2 countries.
Trial summary
The investigators goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique… Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Heat Illness
- How many people
- 148 participants
- Where
- 2 sitesin 2 countries
- Study dates
- Jul 2011to Feb 2016
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The target population will include both civilian DOD beneficiary and active duty military men and women, of any race or ethnicity, between the ages of 18 and 45 years.
Who may be able to join
- Federal Civilian Employee, Active Duty, or DoD Beneficiary
- Between the ages of 18 and 45 years
- Waist circumference ≤ 39.4 inches (100 cm)
- Willing to walk/run on a treadmill
- Willing to undergo exposure in a thermal chamber
- Willing to maintain their current activity patterns, and to abstain from alcohol, caffeine, and tobacco for 24 hours prior to all sessions
- For cases who have suffered from a exertional heat illness / exertional heat stroke, must have a clinically documented heat stroke within the past year
Who cannot join
- History of malignant hyperthermia
- Pregnant or lactating
- Have overt heart disease
- Have systolic blood pressure over 140 mm Hg, or diastolic pressure over 90 mm Hg
- Have a waist circumference > 39.4 inches (100 cm)
- Are older than 45 or younger than 18 years of age
Show all 9Show fewer
- Are anemic
- Are taking psychotropic medication for any mental health disorder
- Are taking other selected medications (glucose lowering, prednisone or beta blockers)
Trial locations and contacts
2 sites in 2 countries.
2 sites in 2 countries
United States1 site
Uniformed Services University of the Health Sciences
Bethesda, Maryland, 20814
About this study
The investigators goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique bio-signature panels to predict those at risk for exertional heat illness (EHI) and guide return to duty following an episode of EHS.
Read the detailed description
Purpose: Our goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique biosignature panels to predict those at risk for exertional heat illness (EHI) and guide return to duty following an episode of EHS.
Research Design: This is a prospective cross-sectional study.
Methodology/Technical Approach: The proposed study will examine multiple biomarkers in a group of 100 individuals who have not had an episode of EHS and a prospective study of 50 persons who have had an EHS event. Control subjects will have biomarker assessments before and after an exercise challenge under thermoneutral (TTT) and thermally challenged conditions (heat tolerance test/HTT); differences in the responses to the two tests will be attributed to the heat. In EHS subjects, blood will be obtained at time of injury and then followed up at 6 weeks according to non-EHS controls. In addition, EHS cases will be prospectively followed at 3, 6, 12, and 18 months after the 6-week post assessment. If they are heat tolerant at 6-weeks as determined by a HTT, subsequent measures will include only blood samples and questionnaires, whereas if they are heat intolerant (HIT) at 6-weeks, subsequent measures will include additional HTTs, along with blood samples and questionnaires. As our previous data indicate, approximately 20% of non-EHS persons are HIT; we will test 100 non-EHS and 50 EHI persons in this study. Thus, data will be evaluated with regard to thermotolerance. Importantly, all control participants will undergo two test sessions (HTT and TTT); to control for an order effect, we will randomize the tests.
- Conditions
- Heat Illness
- Medical subject headings
- Heat Stress Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Controls | Active Duty,DoD Beneficiary, or civilian men and women between the ages of 18 and 45 years, with a waist circumference ≤ 39.4 inches (100 cm) will be asked to participate. | |
| Exertional Heat Illness / Stroke | Active duty men and women between the ages of 18 and 45 years will be asked to participate. They must have a clinically documented heat stroke within the last year; they will not be tested any sooner than six weeks following the heat stroke. Heat stroke for the purpose of this study is defined as: a syndrome of hyperthermia, physical collapse or debilitation, and encephalopathy as evidenced by delirium, stupor, or coma, occurring during or immediately following exertion or significant heat exposure. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Heat tolerance
Heat tolerance is determined by physiologic response to a 2-hour heat tolerance test. During this test, participants with core temperature greater than 38.5 C and/or heart rate greater than 150 bpm are considered heat intolerant.
Measured: 2-hour heat test
Secondary outcomes (3)
Fitness
Body fat and aerobic capacity will be measured to quantify their contribution to heat tolerance.
Measured: 2-hour heat tolerance test
Behavioral correlates of heat tolerance
Questionnaires will be used to assess behavioral correlates of heat tolerance, including measures of sleep impairment and executive dysfunction.
Measured: past month
Perceived heat strain
Measures of perceived heat strain will be recorded to determine how accurately participants perceive that they are working in the heat, and whether this adds diagnostic value to the heat test.
Measured: 2-hour heat tolerance test and 2-hour control test
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2011 (estimated)
- Study startJul 2011
- Primary completionFeb 2016
- Study completionFeb 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Heat IllnessStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 148 participants (actual)
Sponsor and investigators
- Lead sponsor
- Henry M. Jackson Foundation for the Advancement of Military Medicine
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Patricia Deuster, PhD, MPH, Principal investigator, Uniformed Services University of the Health Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01434979
- Sponsor's protocol ID
- G191FY
- Acronym
- Heat3
- Status last verified
- Oct 2019
- First submitted
- 14 Sep 2011
- Last updated
- 11 Oct 2019
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Oct 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exertional Heat Illness: Biomarkers for Prediction and Return to Duty
- ClinicalTrials.gov ID
- NCT01434979
- Acronym / sponsor ID
- Heat3 / G191FY
- Conditions
- Heat Illness
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 148 participants (actual)
- Lead sponsor
- Henry M. Jackson Foundation for the Advancement of Military MedicineUniversity, hospital or other
- Study start
- Jul 2011
- Primary completion
- Feb 2016 (actual)
- Study completion
- Feb 2016 (actual)
- First posted
- 15 Sep 2011 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The investigators goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique bio-signature panels to predict those at risk for exertional heat illness (EHI) and guide return to duty following an episode of EHS.
Detailed description
Purpose: Our goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique biosignature panels to predict those at risk for exertional heat illness (EHI) and guide return to duty following an episode of EHS.
Research Design: This is a prospective cross-sectional study.
Methodology/Technical Approach: The proposed study will examine multiple biomarkers in a group of 100 individuals who have not had an episode of EHS and a prospective study of 50 persons who have had an EHS event. Control subjects will have biomarker assessments before and after an exercise challenge under thermoneutral (TTT) and thermally challenged conditions (heat tolerance test/HTT); differences in the responses to the two tests will be attributed to the heat. In EHS subjects, blood will be obtained at time of injury and then followed up at 6 weeks according to non-EHS controls. In addition, EHS cases will be prospectively followed at 3, 6, 12, and 18 months after the 6-week post assessment. If they are heat tolerant at 6-weeks as determined by a HTT, subsequent measures will include only blood samples and questionnaires, whereas if they are heat intolerant (HIT) at 6-weeks, subsequent measures will include additional HTTs, along with blood samples and questionnaires. As our previous data indicate, approximately 20% of non-EHS persons are HIT; we will test 100 non-EHS and 50 EHI persons in this study. Thus, data will be evaluated with regard to thermotolerance. Importantly, all control participants will undergo two test sessions (HTT and TTT); to control for an order effect, we will randomize the tests.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Controls | – | –Active Duty,DoD Beneficiary, or civilian men and women between the ages of 18 and 45 years, with a waist circumference ≤ 39.4 inches (100 cm) will be asked to participate. |
| Exertional Heat Illness / Stroke | – | –Active duty men and women between the ages of 18 and 45 years will be asked to participate. They must have a clinically documented heat stroke within the last year; they will not be tested any sooner than six weeks following the heat stroke. Heat stroke for the purpose of this study is defined as: a syndrome of hyperthermia, physical collapse or debilitation, and encephalopathy as evidenced by delirium, stupor, or coma, occurring during or immediately following exertion or significant heat exposure. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The target population will include both civilian DOD beneficiary and active duty military men and women, of any race or ethnicity, between the ages of 18 and 45 years.
Key inclusion criteria (7 listed)
- Federal Civilian Employee, Active Duty, or DoD Beneficiary
- Between the ages of 18 and 45 years
- Waist circumference ≤ 39.4 inches (100 cm)
- Willing to walk/run on a treadmill
- Willing to undergo exposure in a thermal chamber
Key exclusion criteria (9 listed)
- History of malignant hyperthermia
- Pregnant or lactating
- Have overt heart disease
- Have systolic blood pressure over 140 mm Hg, or diastolic pressure over 90 mm Hg
- Have a waist circumference > 39.4 inches (100 cm)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Heat tolerance
Time frame: 2-hour heat test
Heat tolerance is determined by physiologic response to a 2-hour heat tolerance test. During this test, participants with core temperature greater than 38.5 C and/or heart rate greater than 150 bpm are considered heat intolerant.
3 secondary outcomes
Fitness
Time frame: 2-hour heat tolerance test
Behavioral correlates of heat tolerance
Time frame: past month
Perceived heat strain
Time frame: 2-hour heat tolerance test and 2-hour control test
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Oct 2019.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Patricia Deuster, PhD, MPH principal investigator
Uniformed Services University of the Health Sciences
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Heat Illness, run by Henry M. Jackson Foundation for the Advancement of Military Medicine at 2 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Oct 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States, Israel. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Heat tolerance (time frame: 2-hour heat test). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Oct 2019.